I'm fine with the common European rat though perhaps they'll use a lesser known rodent.
What about another Raccoon?
Personally I feel Starly and Pidove are the worst regional birds. I hope the regional bird for the 6th gen isn't fat and black/grey.
Taillow is my favourite regional bird. If the upcoming games don't have a regional bird of their own I hope they use Taillow/Swellow as the stand in.